Taking on the tradition of the spellslinger wizard, the Magus version gives up a wider range of abilities in exchange for the primary ability to use guns with their spellstrike and spell combat, but also gets some abilities unique to the archetype. They are a little bit gunslinger, a little bit spellslinger, but mostly still magus.
Weapon and Armor Proficiency
A magus is proficient with all simple and martial weapons, and gains exotic weapon proficiency (one-handed Firearms). A magus is also proficient with light armor. He can cast magus spells while wearing light armor without incurring the normal arcane spell failure chance. Like any other arcane spellcaster, a magus wearing medium armor, heavy armor, or a shield incurs a chance of arcane spell failure if the spell in question has a somatic component. A multiclass magus still incurs the normal arcane spell failure chance for arcane spells received from other classes.
Spellslingers cast one fewer spell of each level than normal. If this reduces the number to 0, he may cast spells of that level only if his Intelligence allows bonus spells of that level.
The spellslinger magus gains the Gunsmithing feat and a battered gun that is identical to the gun a Gunslinger gains at first level. Like a Gunslinger, a spellslinger can use the Gunsmithing feat to restore his battered gun.
Spellslinger Arcane Pool
At 1st level, the magus gains a reservoir of mystical arcane energy that he can draw upon to fuel his powers and enhance his weapon or weapons. This arcane pool has a number of points equal to 1/2 his magus level (minimum 1) + his Intelligence modifier. The pool refreshes once per day when the magus prepares his spells.
At 1st level, a magus can expend 1 point from his arcane pool as a swift action to grant any melee weapon she is holding a +1 enhancement bonus for 1 minute. For every four levels beyond 1st, the weapon gains another +1 enhancement bonus, to a maximum of +5 at 17th level. These bonuses can be added to the weapon, stacking with existing weapon enhancement to a maximum of +5. Multiple uses of this ability do not stack with themselves.
At 4th level, the spellslinger magus may instead add these bonuses to her arcane gun.
At 5th level, these bonuses can be used to add any of the following weapon properties to a melee weapon: dancing, flaming, flaming burst, frost, icy burst, keen, shock, shocking burst, speed, or vorpal. Alternatively, the spellslinger magus may add the following abilities to her arcane gun: dancing, defending, distance, flaming, flaming burst, frost, ghost touch, icy burst, merciful, seeking, shock, shocking burst, spell storing, thundering, vicious, and wounding. The Spellslinger Magus may also choose to split this bonus between one melee weapon and her arcane gun, if preferred. The Spellslinger Magus may still be required to have one free hand in order to use other abilities, such as Spell Combat, this ability does not change that requirement.
Adding these properties consumes an amount of bonus equal to the property’s base price modifier. These properties are added to any the weapon already has, but duplicates do not stack. If the weapon is not magical, at least a +1 enhancement bonus must be added before any other properties can be added. If the Spellslinger Magus is splitting bonuses, both weapons must have a minimum of a +1 enhancement bonus before any other properties can be added. These bonuses and properties are decided when the arcane pool point is spent and cannot be changed until the next time the magus uses this ability. These bonuses do not function if the weapon is wielded by anyone other than the magus.
This ability replaces the standard Arcane Pool magus ability, but counts as an Arcane Pool for the use of any abilities, feats or requirements.
At 1st level, a magus learns to cast spells and wield his weapons at the same time. This functions much like two-weapon fighting, but the off-hand weapon is a spell that is being cast. To use this ability, the magus must have one hand free (even if the spell being cast does not have somatic components), while wielding a light or one-handed melee weapon or one-handed firearm in the other hand. As a full-round action, he can make all of his attacks with his melee weapon or firearm at a –2 penalty and can also cast any spell from the magus spell list with a casting time of 1 standard action (any attack roll made as part of this spell also takes this penalty) or less. If he casts this spell defensively, he can decide to take an additional penalty on his attack rolls, up to his Intelligence bonus, and add the same amount as a circumstance bonus on his concentration check. If the check fails, the spell is wasted, but the attacks still take the penalty. A magus can choose to cast the spell first or make the weapon attacks first, but if he has more than one attack, he cannot cast the spell between weapon attacks.
This ability replaces the standard Spell Combat ability.
At 4th Level, the Spellslinger Magus has the ability to cast spells through a firearm in much the same way as she is able to do with melee weapons. In order to do this, the spellslinger magus must spend one minute to attune a one-handed firearm as an arcane gun. Once this process is done, the firearm remains her arcane gun until she attunes a new one or the existing arcane gun is destroyed.
Arcane guns can be used in two ways. The first allows the spellslinger magus to use Spellstrike with her arcane gun, but only with spells that require a ranged touch attack to hit. This otherwise functions exactly as spellstrike.
Alternatively, a spellslinger can cast any ranged touch attack, cone, line, or ray spells through a his arcane gun. When he casts through the arcane gun, the gun’s enhancement bonus (if any) is a bonus to the spell’s attack rolls or to the spell’s saving throw DCs. Yet there are dangers inherent to this method. If any of the spells’ attack rolls result in a natural 1 (a misfire), or a natural 20 is rolled on any saving throw made against the spell by a target (an overload), the arcane gun gains the broken condition. If the arcane gun already has the broken condition, the gun explodes. When a gun explodes, it lets loose a blast of force, or if the spell has the acid, cold, electricity, or sonic descriptor, it deals that type of energy damage instead. In the case of spells with multiple descriptors, roll randomly among the descriptors to determine the type of damage dealt by the blast. The blast is centered on a single intersection within the spellslinger’s space (spellslinger’s choice) and deals 1d6 points of the appropriate energy damage or force damage per level of the spell cast. Any creature within the blast other than the spellslinger can make a Reflex saving throw to halve the damage. The Reflex save DC is calculated using the spell level of the spell being sacrificed.
This ability can be used in conjunction with Spell Combat.
This ability replaces Spell Recall
The spellslinger magus gains the following Magus Arcana automatically at 6th level.
Quick Clear Arcana (Ex): As a standard action, the spellslinger magus can remove the broken condition from a single firearm she is currently wielding, as long as that condition was gained by a firearm misfire. The spellslinger must spend 1 Arcane Pool point in order to use this ability. Alternatively, if the spellsinger magus spends 2 arcane pool points to perform this arcana, she can perform quick clear as a move-equivalent action instead of a standard action.
This ability replaces the Magus Arcana gained at 6th level.
Starting at 5th level, a spellslinger magus can select one specific type of one-handed firearm (such as a pistol). She gains a bonus equal to her Dexterity modifier on damage rolls when firing that type of firearm. Furthermore, when she misfires with that type of firearm, the misfire value of that firearm increases by 2 instead of 4. Every four levels thereafter (9th, 13th, and 17th), the gunslinger picks up another type of firearm, gaining these bonuses for those types as well.
This ability replaces Medium Armor Proficiency.
At 11th level, as long as the spellslinger magus has at least 1 point in her Arcane Pool, she may activate Arcane Reloading. If she does, she can fully reload a one-handed firearm as a swift action once per round. If she has the Rapid Reload feat or is using an alchemical cartridge (or both), she can reload the weapon as a free action, and may reload and fire multiple times up to her maximum number of attacks.
Furthermore, reloading a one-handed firearm does not provoke an attack of opportunity as long as the spellslinger magus has at least 1 point in her Arcane Pool.
This ability replaces Improved Spell Recall.
At 15th level, the Spellslinger Magus gains the ability to be accurate beyond the realm of normal possibility and even make seemingly impossible shots by weaving some of her innate magic into her shot. As a swift action, the spellslinger magus may add her Intelligence Modifier as an insight bonus to her attack roll on her next firearm attack. This ability may be used in conjunction with spell combat and spell strike.
In addition, she may spend 1 arcane pool point to ignore partial cover and concealment against the target of her next firearm attack. For 2 arcane pool points, she may ignore all forms of cover and concealment, effectively honing in on the target and even bouncing off surfaces or curving around corners. For 3 arcane pool points, she may also ignore all forms of Damage Reduction on the target of her next firearm attack.
This ability replaces Heavy Armor Proficiency.
True Spellslinger Magus
As True Magus, except that the Spellslinger Magus may use this ability with one-handed firearms as well.